<?php

/*
 +-----------------------------------------------------------------------+
 | This file is part of the Roundcube Webmail client                     |
 |                                                                       |
 | Copyright (C) The Roundcube Dev Team                                  |
 |                                                                       |
 | Licensed under the GNU General Public License version 3 or            |
 | any later version with exceptions for skins & plugins.                |
 | See the README file for a full license statement.                     |
 |                                                                       |
 | PURPOSE:                                                              |
 |   Spellchecking backend implementation to work with Googiespell       |
 +-----------------------------------------------------------------------+
 | Author: Aleksander Machniak <machniak@kolabsys.com>                   |
 | Author: Thomas Bruederli <roundcube@gmail.com>                        |
 +-----------------------------------------------------------------------+
*/

/**
 * Spellchecking backend implementation to work with a Googiespell service
 */
class rcube_spellchecker_googie extends rcube_spellchecker_engine
{
    public const GOOGIE_HOST = 'https://spell.roundcube.net';

    private $content;

    /**
     * Return a list of languages supported by this backend
     *
     * @see rcube_spellchecker_engine::languages()
     */
    #[Override]
    public function languages()
    {
        return [
            'am', 'ar', 'ar', 'bg', 'br', 'ca', 'cs', 'cy', 'da',
            'de_CH', 'de_DE', 'el', 'en_GB', 'en_US',
            'eo', 'es', 'et', 'eu', 'fa', 'fi', 'fr_FR', 'ga', 'gl', 'gl',
            'he', 'hr', 'hu', 'hy', 'is', 'it', 'ku', 'lt', 'lv', 'nl',
            'pl', 'pt_BR', 'pt_PT', 'ro', 'ru',
            'sk', 'sl', 'sv', 'uk',
        ];
    }

    /**
     * Set content and check spelling
     *
     * @see rcube_spellchecker_engine::check()
     */
    #[Override]
    public function check($text)
    {
        $this->content = $text;

        if (empty($text)) {
            return true;
        }

        $this->matches = $matches = [];

        $rcube = rcube::get_instance();
        $client = $rcube->get_http_client();

        // spell check uri is configured
        $url = $rcube->config->get('spellcheck_uri');

        if (!$url) {
            $url = self::GOOGIE_HOST . '/tbproxy/spell?lang=';
        }
        $url .= $this->lang;
        $url .= sprintf('&key=%06d', !empty($_SESSION['user_id']) ? $_SESSION['user_id'] : 0);

        $gtext = '<?xml version="1.0" encoding="utf-8" ?>'
            . '<spellrequest textalreadyclipped="0" ignoredups="0" ignoredigits="1" ignoreallcaps="1">'
            . '<text>' . htmlspecialchars($text, \ENT_QUOTES, RCUBE_CHARSET) . '</text>'
            . '</spellrequest>';

        try {
            $response = $client->post($url, [
                    'connect_timeout' => 5, // seconds
                    'headers' => [
                        'User-Agent' => 'Roundcube Webmail/' . RCUBE_VERSION . ' (Googiespell Wrapper)',
                            'Content-type' => 'text/xml',
                    ],
                    'body' => $gtext,
                ]
            );
        } catch (Exception $e) {
            // Do nothing, the error set below should be logged by the caller
        }

        if (empty($response)) {
            $this->error = isset($e) ? $e->getMessage() : 'Spelling engine failure';
        } elseif ($response->getStatusCode() != 200) {
            $this->error = 'HTTP ' . $response->getReasonPhrase();
        } else {
            $response_body = $response->getBody();
            if (preg_match('/<spellresult error="([^"]+)"/', $response_body, $m) && $m[1]) {
                $this->error = "Error code {$m[1]} returned";
                $this->error .= preg_match('/<errortext>([^<]+)/', $response_body, $m) ? ': ' . html_entity_decode($m[1]) : '';
            }

            preg_match_all('/<c o="([^"]*)" l="([^"]*)" s="([^"]*)">([^<]*)<\/c>/', $response_body, $matches, \PREG_SET_ORDER);

            // skip exceptions (if appropriate options are enabled)
            foreach ($matches as $idx => $match) {
                $word = mb_substr($text, $match[1], $match[2], RCUBE_CHARSET);
                // skip  exceptions
                if ($this->dictionary->is_exception($word)) {
                    unset($matches[$idx]);
                }
            }
        }

        $this->matches = $matches;

        return count($this->matches) == 0;
    }

    /**
     * Returns suggestions for the specified word
     *
     * @see rcube_spellchecker_engine::get_words()
     */
    #[Override]
    public function get_suggestions($word)
    {
        $this->check($word);

        if (!empty($this->matches[0][4])) {
            $suggestions = explode("\t", $this->matches[0][4]);
            if (count($suggestions) > self::MAX_SUGGESTIONS) {
                $suggestions = array_slice($suggestions, 0, self::MAX_SUGGESTIONS);
            }

            return $suggestions;
        }

        return [];
    }

    /**
     * Returns misspelled words
     *
     * @see rcube_spellchecker_engine::get_suggestions()
     */
    #[Override]
    public function get_words($text = null)
    {
        if ($text) {
            $this->check($text);
        } else {
            $text = $this->content;
        }

        $result = [];

        foreach ($this->matches as $m) {
            $result[] = mb_substr($text, $m[1], $m[2], RCUBE_CHARSET);
        }

        return $result;
    }
}
